I've been watching this on Netflix instant viewing. I saw the Christopher Eccleston doctor in a few episodes and thought, "Neat, he's a lively fellow." I was really unsure about watching anything after Season (Series) 1.
But David Tennant has grown on me like a golden tumor (even if I could get rid of it, I'm not sure I'd want to). And the stories are awesome!
I find it odd, but I'm told it's "always been this way" that the costumes and makeup are seemingly top-knotch and the CGI leaves a little to be desired. However, the eye candy is not what's captivated me. The writing is surprisingly (and consistently) witty and humorous, even to me, an American with no real knowlege of British colloquialism. The acting is superb, given that it's "just" a tv show.
One tiny thing still irks me about the show, and that's the endings. A lot of the endings seem to be in the last five minutes of the program, and seem like they were rushed in every stage of production.
Overall, though, I have been loving it.
Edit: Oh ya, I'm on season 3 now.